Definitions

Neap tides
A tide that occurs when the difference between high and low tide is least; the lowest level of high tide. Neap tide comes twice a month, in the first and third quarters of the moon. Contrast with Spring Tide

New moon
A phase of the moon in which none of the moons face is visible (when the moon is dark)

Nonpoint source pollution (NPS)
Pollution discharged over a diffuse area , such as city streets, neighborhood yard, and agricultural fields and not from one specific location

Nuclear Energy
Energy produced by particles such as those released by the sun or energy that comes from splitting atoms of radioactive materials, such as uranium